72 DESCARTES. 



results of five or six principal difficulties which I 

 have surmounted, and my encounters with which I 

 reckoned as battles^ in which victory declared for 

 me. I will not hesitate even to avow my belief 

 that nothing further is wanting to enable me fully 

 to realize my designs than to gain two or three 

 similar victories; and that I am not so far advanced 

 in years but that, according to the ordinary course 

 of nature, I may still have sufficient leisure for this 

 end. But I conceive myself the more bound to hus 

 band the time that remains the greater my expecta 

 tion of being able to employ it aright, and I should 

 doubtless have much to rob me of it, were I to pub 

 lish the principles of my Physics: for although they 

 are almost all so evident that to assent to them no 

 more is needed than simply to understand them, and 

 although there is not one of them of which I do not 

 expect to be able to give demonstration, yet, as it is 

 impossible that they can be in accordance with all 

 the diverse opinions of others, I foresee that I 

 should frequently be turned aside from my grand 

 design, on occasion of the opposition which they 

 would be sure to awaken. 



It may be said, that these oppositions would be 

 useful both in making me aware of my errors, and, 

 if my speculations contain anything of value, in 

 bringing others to a fuller understanding of it; and 

 still farther, as many can see better than one, in 

 leading others who are now beginning to avail them 

 selves of my principles, to assist me in turn with 

 their discoveries. But though I recognise my 

 extreme liability to error, and scarce ever trust to 



